[PATCH v2 03/33] ibmvfc: check for NULL evt in implicit LOGO and target delete path

Unlike ibmvfc_tgt_implicit_logout the ibmvfc_tgt_implicit_logout_and_del
path fails to check for a NULL evt returned from
ibmvfc_get_reserved_event and passes that directly to ibmvfc_send_event
which will unconditionally derefence the evt.

Check for a NULL evt and perform same escalation as
ibmvfc_implicit_logout.

Signed-off-by: Tyrel Datwyler <[email protected]>
---
 drivers/scsi/ibmvscsi/ibmvfc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 72317d7840a5..59102dd1c787 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -4406,6 +4406,14 @@ static void ibmvfc_tgt_implicit_logout_and_del(struct ibmvfc_target *tgt)
 	evt = __ibmvfc_tgt_get_implicit_logout_evt(tgt,
 						   ibmvfc_tgt_implicit_logout_and_del_done);
 
+	if (!evt) {
+		vhost->discovery_threads--;
+		ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
+		kref_put(&tgt->kref, ibmvfc_release_tgt);
+		__ibmvfc_reset_host(vhost);
+		return;
+	}
+
 	ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_LOGOUT_RPORT_WAIT);
 	if (ibmvfc_send_event(evt, vhost, default_timeout)) {
 		vhost->discovery_threads--;
-- 
2.55.0